Figure 2.

Intratumoral injection of Cont-VV or hIL-7/mIL-12-VV increases ICOS expression in PD-1⁻CD8⁺ T cells

(A–G) BALB/c mice bearing subcutaneous CT26.WT tumors (about 50 mm³) were intratumorally injected with PBS, 2 × 10⁷ PFUs of Cont-VV, or 2 × 10⁷ PFUs of hIL-7/mIL-12-VV. Six days after treatment, tumor-infiltrating CD8⁺ T cells were analyzed by flow cytometry (n = 10). (A) Representative plots of PD-1 and ICOS expression in intratumoral CD8⁺ T cells. (B) Percentage of PD-1⁻ cells in intratumoral CD8⁺ T cells. (C) Percentage of ICOS⁺ cells in intratumoral PD-1⁻CD8⁺ T cells. (D–F) Percentage of Tim-3⁺ cells (D), GITR⁺ cells (E), and TIGIT⁺ cells (F) in intratumoral PD-1⁻CD8⁺ T cells. (G) Percentage of ICOS⁺ cells in intratumoral PD-1⁺CD8⁺ T cells. (H and I) CT26.WT tumors were treated with PBS, 2 × 10⁷ PFUs of Cont-VV, or 2 × 10⁷ PFUs of hIL-7/mIL-12-VV every other day for a total of three times. Tumors were collected 15 days after the first treatment, and intratumoral CD8⁺ T cells were analyzed by flow cytometry (n = 10). (H) Representative plots of PD-1 and ICOS expression. (I) Percentage of ICOS⁺ cells in PD-1⁻CD8⁺ T cells. (J and K) LLC tumors in C57BL/6 mice were treated with PBS, 2 × 10⁷ PFUs of Cont-VV, or 2 × 10⁷ PFUs of hIL-7/mIL-12-VV. Tumors were collected 6 days after treatment, and intratumoral CD8⁺ T cells were analyzed (n = 10). (J) Representative plots of PD-1 and ICOS expression. (K) Percentage of ICOS⁺ cells in PD-1⁻CD8⁺ T cells. Mean ± SEM is shown. ∗∗p < 0.01; ∗∗∗p < 0.001 by Mann-Whitney U test. N.S., not significant.